WASHINGTON — Defense Secretary Chuck Hagel defended President Obama’s proposed cuts to the military on Thursday as the best approach as the Pentagon grapples with smaller, deficit-driven budgets.

Dismissing a suggestion that he was Obama’s hired gun to slash the defense budget, Hagel told the House Armed Services Committee that the significant reductions in projected spending was the law long before he took over at the Pentagon six weeks ago.

Hagel said he has to be realistic about the cuts of $487 billion over 10 years that Congress and Obama agreed to in August 2011 as well as the additional, automatic cuts of $41 billion that kicked in March 1.

Advertisement

Representative Mac Thornberry, Republican of Texas, said the widespread view was Hagel was tapped for the top Pentagon job to cut the defense budget.

‘‘The cuts you’re talking about occurred long before I got here,’’ Hagel told the panel. ‘‘As to my responsibilities . . . [it’s to] lead, preside over an institution with only one mission to secure this country. . . . Yet part of my job is to manage.’’

The Pentagon chief said Obama’s instruction to him ‘‘wasn’t to cut the heart out of the Pentagon.’’

Hagel faced resistance from some in Congress to proposals in the $526.6 billion Pentagon budget for fiscal 2014 that calls for another round of domestic base closings, increases in military health care fees, and a smaller pay raise of 1 percent for personnel.

Hagel called the base closing system ‘‘imperfect,’’ but argued it was a ‘‘comprehensive and fair approach’’ that will result in considerable savings in the long term. He insisted that the Pentagon needed to address increasing costs of personnel benefits and excess installations to ensure that the military could carry out its mission.

Advertisement

He said the department is undergoing a far-reaching review to be completed by May 1 and indicated that further cuts are possible.

The hearing marked Hagel’s first trip back to Capitol Hill since his bruising Senate confirmation fight in February.

In a time of fiscal austerity, Tea Party figures and other conservatives have clamored for significant cuts in spending as the federal government grapples with a nearly $1 trillion annual deficit. Yet some have rejected cost-cutting changes envisioned by the Pentagon, including domestic base closings, an increase in health care fees for military retirees and the cancellation of some weapons.

The Pentagon is trying again with the new budget, seeking another round of base closings in 2015, requesting the retiree health care fee hike and proposing to terminate a version of the Global Hawk unmanned aircraft.

In fact, the budget proposal reflects a degree of wishful thinking on the part of the Pentagon. It ignores the automatic, across-the-board budget cuts that the military is dealing with daily.

Advertisement

The proposal calls for a base Pentagon budget of $526.6 billion — $52 billion more than the $475 billion level established by the spending cuts set in the budget agreement between Obama and congressional Republicans in August 2011. Fiscal conservatives have accepted the cuts as a sure-fire way to reduce the federal deficit, and they have shown no inclination to abandon the cuts despite the outcry of defense hawks and senior Pentagon officials who fear an erosion of United States military might.

The budget plan also includes an $88.5 billion placeholder for additional war costs in Afghanistan.